The present invention relates to eyeglasses of the type which have no mounting and have supplementary lenses added to the eyeglasses.
Eyeglasses called xe2x80x9cextralightxe2x80x9d have been known for a long time. The lenses of these eyeglasses are deprived of mounting and are directly connected to the central small bridge and to the extremity of the two lateral rods.
This new type of eyeglass lens therefore imposed on manufacturers in this field the task of revising the devices capable of supporting the lenses, specifically with respect to the system of connecting the riser to the lens. In the present state of the art, the most common constructive solution consists of anchoring the lens with the extremity of the riser, that is with the terminal part of the rod comprised between the hinge and the lens itself.
The clamping of the lens without any mounting in the proper position with respect to the rods and the small central bridge is obtained by providing the extremities of connection of the rod and the small bridge to be particularly shaped, for instance with a fork shape, which becomes inserted on some openings formed in the same lens. In order to make sure that the processing is more rigid and to avoid that, with use, the lenses lose their optimal inclination with respect to the face of the individual who is using the glasses, occasionally there has been provided that the extremities of the riser and the small bridge be slightly imbedded in the lenses, as it has been described by way of example in the documents WO-A-96/33438 and U.S. Pat. No. 5,847,800.
The use of additional lenses, commonly called supplementary, has also been known. These supplementary lenses are positioned in front of the normal lenses, with different objects, from simple parasol lenses to enlargement lenses, used for instance in microsurgery for views at a short distance and progressive lenses.
Among the many methods for anchoring the supplementary lenses the so called magnetic attack is used. In this method small magnetic plates are mounted on the frame of the eyeglasses, the plates attract other magnetic plates present in the supplementary structures as described for instance in the document WO-A-96/37800.
In the present state of the art the magnetic attachment is carried out between the two planar surfaces of two counterposed magnets which fit together, so that the optimum reciprocal attraction force is the force directed horizontally, that is when the two magnets in addition to fitting together become parallel with respect to each other.
This method of attachment has two drawbacks. The first drawback is due to the fact that it is not always possible to carry out the application of the supplementary lens on the principal mounting with the necessary exactness. The second drawback is due to the fact that a single accidental bump of the eyeglasses is sufficient to cause the supplementary lens to be moved away from its regular position, while remaining magnetically hooked with the result that the vision of the user becomes imperfect.
These drawbacks have been overcome only partially by means of supplementary lenses on a frame which is sufficiently rigid, the frame being provided with lateral projections which have mechanical or magnetic hooks, the hooks being anchored on the rods or on the riser of the principal mounting, preferably corresponding to the hinge. By way of example of this type of mounting, there may be mentioned British A-2338566, EP-A-0773463, EP-A-0743545, WO-A-97/16761 and U.S. Pat. No. 5,877,838.
One object of the present invention is to provide an attachment system for the riser and the small bridge to the lenses to be mounted on eyeglasses, of the type free of mounting, which offers advantages over the similar known products.
Specifically the attachment system of the riser of the invention is characterized by simplicity of execution, minimum cluttering and pleasant aesthetic appearance.
Another object of the invention is to provide a system of attachment of the riser and the central small bridge to the lenses free of mounting which is sufficiently strong and easily cleansed.
Still another object of the invention is to provide a system of attachment of the riser and the small bridge to the lenses free of mounting which does not depend on the thickness and the shape of the lenses.
Another object of the invention is to provide a system for attachment of the riser to the lens which permits the application to the eyeglass in a rapid and sure manner.
A further object of the invention is to provide supple-mental lenses, free of mounting and having magnetic small plates, characterized by the fact that they allow the user to position them extremely exactly and rapidly on the principal eyeglass.
Still another object is to provide small magnetic plates of minimum thickness which may be mounted on the supplemental lenses.
A further object of the invention is to provide small magnetic plates which require an anchoring system on the body of the supplemental lens which is simple, of rapid execution, minimum cluttering and also valid aesthetically.
The inherent objects to the system of attachment of the riser and the small bridge to the lenses are achieved by providing that the extremities of the riser and the central small bridge have a terminus which is inserted from the internal surface of the lens within corresponding niches shaped as a lozenge or diamond, the niches being formed on the internal surface of the lens and having an opening through the lens on the bottom wall. In addition the invention provides that the terminal portion have a braid, male or female, which has a protruding head which protrudes through the above opening from the opposite part of the lens.
A first embodiment of the braid is constituted by a threaded hole, formed in the terminal portion mentioned hereinabove, which is engaged in the niche formed on the lens and on which the braid is screwed, through the opening formed on the lens, by means of a threaded pin, provided with a head, which is inserted from the external part of the lens.
According to a second embodiment, the braid is constituted by an element protruding beyond the terminal portion and which engages in the niche formed in the lens and through the opening formed on the lens to allow the screwing of a head from the external part of the lens.
In both embodiments the niche formed on the internal wall of the lens and shaped as a diamond, is disposed in a manner that its longitudinal axis is perpendicular to the axis of the opening formed in the lens, which is necessary to allow the passage of the threaded element.
Constructively the invention provides that the riser is shaped in a manner to present two filiform elements and a small block between the two filiform elements, all of them being disposed reciprocally superimposed with the two filiform elements projecting to the rear from the lens up to the hinge while the intermediate small block which is of limited length and a little greater than the depth of the niche, constitutes the threaded body, by means of a threaded opening or a threaded protruding pin.
With this construction the clamping and support of the lenses are assured as in the similar embodiments but there is also the advantage that on the external surface of each of the two lenses only two heads protrude, that is those heads being necessary for the threaded connection of the riser and the small bridge and permitting application to the eyeglass in a rapid and simple manner supplemental lenses such as filters or parasol lenses. In fact the inherent objects that the supplemental lenses obtain due to the fact that supplemental lenses are provided on their internal surfaces with magnetic blocks which are disposed in such a manner that when the supplemental lenses are positioned above the lenses of the eyeglasses, the magnetic blocks are anchored, due to a magnetic effect on the heads so that they constitute the support of the supplemental lenses. Specifically, the exact positioning of the supplemental lenses over the main eyeglass lenses is obtained by providing the magnetic plate with a seat in a cavity within which the corresponding protrusion of the main lens is present when the supplemental lens is placed in contact therewith.